中国西南部强震带大震复发机制

我国西南部鲜水河断裂带、红河断裂带、安宁河断理解带和龙门山断裂带四个测区内，用Ｘ射线法 得的宏观残余应力场和用震源机制解Ｐ轴显示的发震时现今应力场的水平最大主压应力方向基本吻合。这种叠加应力场的水平最大主压力分布方向与发震断裂带总体走 交角约为４０－５５°左右，使断裂带易于发生剪切错动。宏观残余水平最大剪应 值区的分布，也与区内大震震中的分布基本吻合，岩石裂面在３００℃和３００ＭＰａ围压下经１０天     

新疆南天山环境应力场特征

基于新疆强震固定台和流动观测记录的主要和余震加速度资料，选用了三个分向记录都完整的３７次地震。震级范围为１．８－６．８级，震中距为几至几十公里。根据用位错理论二维断裂力学模式推导的震源峰值、加速度与环境剪应力场关系式计算了新疆南天山环境剪应力值。计算结果表明，新疆南天山环境应力平均值偏高，这与新疆处于特殊构造环境条件有关。     

东北大部旱情缓解 粤闽局地暴雨成灾──1997年5月

东北大部旱情缓解粤闽局地暴雨成灾—１９９７年５月—徐良炎（国家气候中心，北京１０００８１）５月份，东北大部、华北北部及黄淮等地普降喜雨，旱情缓解；西北东部、华北西部等地降水偏少，旱情持续或发展。南方大部地区雨水比较调匀，无大范围旱涝发生，但华南局地遭...     

线性和非线性风应力对海-气耦合波的影响

在略去Ｒｅｙｌｅｉｇｈ摩擦和Ｎｅｗｔｏｎ冷却的条件下，采用定常的线性大气模式和半地转近似的非线性海洋模式，讨论了线性和非线性风应力对海－气耦合Ｒｏｓｓｂｙ波的影响，结果表明，当耦合波处于非线性不稳定的情况下，线性和非线性风应力均可产生孤立波，不同之处在于，非线性风应力所产笺波图像具有间断特点，波能的急剧聚集有可能使波的性质发生变化。     

东北输油管道锦县,盖县,海城段地基土抗液化强度研究

对东北输油管道锦县，盖县，海城段的粉土细砂，中砂，粉砂进行了振动液化试验，取得了和类土的τｄ－ｌｏｇＮｆ曲线，τｄ／σ′－ｌｏｇＮｆ曲线，为在以上地区进行液化判别提供了重要的基础资料，同时也为研究其它的地区相同土质的振动性能提供借鉴。     

DOES WIND STRESS DEPEND ON SEA-STATE OR NOT? – A STATISTICAL ERROR ANALYSIS OF HEXMAX DATA

There have been several claims, either explicit or by implication, either based on experimental evidence or on theoretical reasoning, that the wind stress is modified by the stage of development of the wind sea. However, the overall evidence is weak, because theories are still incomplete and because it is questionable whether the sea-state effect, which is of the order of 10%, can be separated from experimental noise, which is of the order of 20%. In this paper a rigorous statistical analysis of HEXMAX data is pursued in order to establish the significance of sea-state effects. It appears that the enhanced drag, especially at high winds, which has already been established by previous analyses, cannot be attributed to the effect of young waves. The analysis provides no clues for the actual mechanism, which could be related to breaking or shoaling waves. As the effect of sea-state on wind stress is much smaller than the experimental noise level, it is hard to detect. Nevertheless, HEXMAX seems to contain a wave effect that is at the edge of statistical significance. It is, however, not the wave age itself that influences the drag, but a parameter involving wave height.Because the HEXMAX evidence is only indicative, we conclude that the issue set out in this paper cannot be answered on the basis of the HEXMAX data alone. It is recommended that error analyses are also carried out for other relevant observational data sets and that new measurements with suppressed noise will be taken up.     

上海地区超高层建筑桩基沉降计算方法探讨

本文根据已有的建筑经验,应用明特林应力分布理论及双层地基概念和土的临界应力的分析,提出了更符合实际的沉降计算方法,并论证了在第三类土层排列区(即埋深30～40mm的⑦层粉砂层)超高层桩基设置的可能性,以大大减少工程造价。     

桩端沉降测量对试桩成果分析的意义

桩端沉降测量和试桩资料的分析结果表明,桩在传递上部荷载与地基土之间产生的应力应变过程,表现为桩的弹性杆件和地基土的弹—塑性变形特征。从而对受荷桩,尤其是长柱和超长桩的应力应变特征有了更切合实际的认识。     

岩体水力学基础(三)──岩体渗流场与应力场耦合的集中参数模型及连续介质模型

本文在分析了岩体系统的结构性和水力学特征后，提出了岩体渗流场与应力场耦合数学模型的机理分析、混合分析及系统辨识建模方法。运用系统辨识方法建立了岩体渗流场与应力场耦合的集中参数模型，并应用于解决实际问题；运用机理分析和混合分析方法建立了岩体渗流场与应力场双场耦合及与温度场三场耦合的连续介质分布参数模型。     

Modelling the compliance of crustal rock—II. Response to temporal changes before earthquakes

There have been several claims that seismic shear waves respond to changes in stress before earthquakes. The companion paper develops a stress-sensitive model (APE) for the behaviour of low-porosity low-permeability crystalline rocks containing pervasive distributions of fluid-filled intergranular microcracks, and this paper uses APE to model the behaviour before earthquakes. Modelling with APE shows that the microgeometry and statistics of distributions of such fluid-filled microcracks respond almost immediately to changes in stress, and that the behaviour can be monitored by analysing seismic shear-wave splitting. The physical reasons for the coupling between shear-wave splitting and differential stress are discussed.
In this paper, we extend the model by using percolation theory to show that large crack densities are limited at the grain-scale level by the percolation threshold at which interacting crack clusters lead to pronounced increases in rock-matrix permeability. In the simplest formulation, the modelling is dimensionless and almost entirely constrained without free parameters. Nevertheless, APE modelling of the evolution of fluid-saturated rocks under stress reproduces the observed fracture criticality and the narrow range of shear-wave azimuthal anisotropy in crustal rocks. It also reproduces the behaviour of temporal variations in shear-wave splitting observed before and after the 1986, M = 6, North Palm Springs earthquake, Southern California, and several other smaller earthquakes.
The agreement of APE modelling with a wide range of observations confirms that fluid-saturated crystalline rocks are stress-sensitive and respond to changes in stress by critical fluid-rock interactions at the microscale level. This means that the effects of changes in stress and other parameters can be numerically modelled and monitored by appropriate observations of seismic shear waves.